1. Field of the Invention
This invention relates to an image processing apparatus such as copying machines and printers which form images on a transfer member by electrophotographic process, and a fixing apparatus which is mounted on the image processing apparatus and fixes developer on a transfer member to the transfer member.
2. Description of the Related Art
It is known that, in copying machines and printers using electric process, toner images formed on a photosensitive drum is transferred to a transfer member, and then the toner images fused by a fixing apparatus including a heating roller and a pressurizing roller is fixed onto the transfer material.
In recent years, demand for high-speed image processing apparatuses has increased, and fixing rollers having high heat capacity have been used to perform image processing at high speed. However, even when electric power supplied to the heater is increased to increase the heat capacity of the fixing roller, increase in temperature of the fixing roller cannot follow increase in temperature of the heater. Therefore, it is necessary to increase the electric power supplied to the heater.
Further, if sufficient electric power to be supplied to the heater cannot be secured, there is the problem that the time required to increase the temperature of the fixing roller to a certain fixing temperature is not shortened and thus a long warm-up time is required.
For example, as disclosed in Jpn. Pat. Appln. KOKAI Pub. No. 2005-17658, known is a technique in which thermal energy of a fixing heater such as surplus heat is converted into electric energy by a thermoelectric converter, electric power output from the thermoelectric converter is stored in a storage circuit, and the electric power is supplied to the fixing heater when the fixing apparatus is started up.
However, thermoelectric converters leak much heat, and there is the possibility that surplus heat of the fixing apparatus is taken by surrounding frame members. Therefore, the function of the thermoelectric converters is not effectively used.
Further, as disclosed in Jpn. Pat. Appln. KOKAI Pub. No. 2002-64941, known is a technique in which heat generated by a microprocessor is converted into electric energy by a Peltier device, and thereby a secondary battery is charged. If the apparatus is in a power-saving mode and a power-supply circuit is turned off, the secondary battery discharges electric power, and the electric power is supplied to a RAM, an image memory and a subsidiary CPU.
Furthermore, Jpn. Pat. Appln. KOKAI Pub. No. 10-208873 discloses a heating apparatus having heating means such as a magnetron and a heater, which heats cooked food, provided with a thermoelectric converter which converts waste cooking heat of the cooked food, waste heat of the magnetron, and surplus heat of the heater into electric power.